Projects per year
Unlike single photon absorption, the rate of multiphoton absorption processes is dependent on the polarization state of the exciting optical field. Multiphoton absorption spectroscopy is predominantly carried out with an exciting light source which is structured and polarized in a 2D sense in the transverse (x,y) plane, but homogeneous along the direction of propagation (z). Here we study two-photon absorption (TPA) with tightly focused optical vortices, where the spatial confinement generates significant longitudinal components of the electromagnetic fields in the direction of propagation, producing a 3D structured optical field at the focal plane. We discover that the additional polarization degree of freedom in the z direction for 3D structured light produces novel results in TPA compared to the preceding paraxial source excitation.
- 1 Active